On the contrary, I believe the information about Longbeards and the timings help paint a clearer picture of what was going on.
Firstly, from that point on in the timeline (2.40am until 3.40am), there are so many possibilities that could happen and I understand why the State presented their take on that hour. I'd like to have heard what she was intending to finish with in Closing, bur for now we have to go with what was said...
My opinion now is
Heather was travelling to Longbeards at 2.40am. (Did they arrange to meet at Longbeards an hour after the 4 minute payphone call?)
She spam called the payphone on her journey and when she got there.
She got sick of waiting on Sidney at around 3am (20 minutes late?), so decided to head back home.
On that long straight of road outside Longbeards she passed the F150 on its way to Longbeards. (one or both of them would have flashed their lights to acknowledge)
She turned off the long straight road and did a U-turn at the housing estate at Plantation and headed back to Longbeards parking lot.
Sidney's phone is switched on.
She would have arrived and parked close to where the F150 was already parked.
She would have seen Sidney and got out of her car with her keys and phone.
I believe at this point she was jumped and taken to another place by others (remember that $5k?).
Sidney got into Heather's car with her phone and left the lot. He stopped just outside Longbeards to adjust the seating/mirrors in the car and then drove to PTL via Heather's apartment. I believe the original plan was to drop the car off at her appt, but that changed for some reason.
Sidney was using Heather's phone and when he got to PTL he was beyond frantic calling his own cell as code to say he was at the picking up/dropping off place - PTL.
Heather's phone was tossed into the lake as far as he could throw it. The water would very quickly make the phone go dead.